package 面试.遍历算法.String类型题目;

public class 字母大写小写互转 {
    public static void main(String[] args) {
        String str = "adfadfadABCD";
        str = str.toLowerCase();
        str = str.replaceFirst(str.charAt(0) + "",(str.charAt(0) + "").toUpperCase());
        System.out.println(str);
    }
}
